Cupriferous benzthiazole disazo dyestuffs



Patented v Aug. 10, 1954 UNITED STATES PATENT OFFICE 2,686,177 GUPRIFEROUS BENZTHIAZOLE DISAZO DYESTUFFS Raymond Gunst, Binningen, Switzerland, as-

signor to Ciba Limited Basel, Switzerland, a

No Drawing. Application February 2, 1953, Serial No. 334,712

Claims priority, application Switzerland August 25, 1949 7 Claims. (01. 260146) This application is a continuation in part of my copending application Serial No. 180,697, filed August 21, 1950. The present invention is based on the observation that the cup riferous disazc dyestuffs of the formula are very valuable dyestuffs. In this Formula 1,. R. stands for a naphthalene radical containing at least one sulfonic acid group, the azo and the -O-Cugroup. being in ortho-position to each another. By virtue of the presence of the benzthiazole moiety, the said dyestuffs may be designated cupriferous benzthiazole disazo dyestufis.

The cupriferous disazo dyestuffs corresponding to the Formula 1 can be obtained by subjecting disazo dyestuffs which correspond to the formula a1kyl- O 0 -alkyl H O I I 0 N Hoes S CH3 acid or 1-benzoyl-amino-8-hydroxynaphthalenepreferably carried out first since it is possible, and metrical dyestuff is obtained when the tetrazotized 3 :3-dialkoxy-4 4-diaminodiphenyl is 5 coupled twice with 2-[4'-(8"-hydroxynaphthyl- [2''] aminophenyD] 6 methyl benzthiazole-X 6 -disulfonic acid.

The sequence of the two couplings may be as desired. As a rule, the coupling with the 244'- (8 hydroxynaphthyl [2"] aminophenyl) l- G-methyl-benzthiazole-i:6"-disulfonic acid is often advantageous, to couple this component with the tetrazo compound in a weakly acid medium, for example at a pH ranging from 5 to 7, and, surprisingly, the coupling carried out in an N S 0 3H in which R represents a naphthalene radical with at least one sulfonic acid group, which radical is coupled in ortho-position to the hydroxyl groups, to the action of an agent providing copper, under conditions such, that splitting up of the -Oalkyl groups takes place with formation of the ortho:ortho'-dihydroxyazo copper complexes.

The disazo dyestuffs of the Formula 2 can be obtained by coupling a tetrazotized 3 :3'-dia1koxy- 4 4'-diaminodiphenyl, especially 3 3'-dimethoxy- 40 4:4'-diaminodiphenyl, in either sequence, on one side with 2- [4- (8 -hydroxynapl1thyl- [2 aminophenyD] 6 methyl benzthiazole-X:6" disulfonic acid and on the other side with a coupling component of the naphthalene series containing at least one sulfonic acid group and coupling in ortho-position to a hydroxyl group. As such naphthalene components coupling in ortho-position to a hydroxyl group there may be mentioned hydroxynaphthalene monosulfonic acids, such as 1hydroxynaphthalene-4- or -5- sulfonic acid or 2-hydroxy-naphthalene-6-sulfonic acid. Hydroxynaphthalene disulfonic acids, such as l-hydroxynaphthalene-3:6- or 4:8-disulfonic acid or 2-hydroxynaphthalene- 3 :G-disulfonic acid may also be employed. More- 3:6-disulfonic acid may be employed. A symover, amino-hydroxynaphthalene-sulfonic acids, especially those of which the amino group contains substituents, such as Z-phenylamino-S-hy- 6 droxynaphthalene-7-sulfonic acid -3'- carboxylic acid medium also takes place in the 7"-position of this component. Even when the above mentioned symmetrical dyestuff is to be prepared coupling may be carried out in two stages, viz. in a slightly acid medium with the first molecular proportion of 2-[4' (8" hydroxynaphthyl- [2"l-aminophenyl)l 6 methyl benzthiazole- X:6"-disulfonic acid and then in an alkaline medium with the second molecular proportion of this coupling component.

A method for the preparation of the 2- [4'- (8"- hydroxynaphthyl [2"] aminophenyD] 6- methyl -benzthiazole-X:6-disulfonic acid corre SOaH 0 NH C CH HOQS S a 3 4 or absence of an excess of ammonia, the copperstirring the tetrazo compound cannot be detected ing is carried out in an aqueous medium for any longer and the solution is then caused to flow several hours at a temperature in the neighborinto a solution of a further 28 parts of 2-[ l'-(8"- hood of 100C. Of particular advantage in many hydroxynaphthyl [2"] aminophenylll 6- cases is the process according to which the op- 5 methyl-benzthiazole-X:6"-disulfonic acid, diseration is conducted in the presence of hydroxysolved in 200 parts of water with the addition alkylamines, especially ethanolamine or of copper of 35 parts of anhydrous sodium carbonate. The complexes derived therefrom. second coupling proceeds slowly. When it has With regard to the formulae of the cupriferous come to an end, the reaction mi turc is heated dyestuffs it should be explained that these for- 10 and the disazo dyestufi is salted out and filtered mulae undoubtedly represent the correct stoichiooff. metric quantities of copper and the correct posi- In order to transform the dyestuff into its tion of the copper atom in the complex, but the complex copper compound, the filter cake is disdistribution of the main and secondary valences solved in 700 parts of water at 95 C., an aqueous in the complex union of the copper has not yet ammoniacal solution of cupric tetrammine sulbeen established with certainty. The new fate, the copper content of which corresponds to cupriferous disazo dyestuffs of the Formula 1 can parts of crystallized cupric sulfate, and 10 be employed for the dyeing and printing of a parts of monoethanolamine are added. After wide variety of materials, such as wool and silk, twelve hours stirring at 90-95 C. the cupriferous but especially fibers containing cellulose, such as 20 disazo dyestuii of the formula Hols /N\ OGu-(') ()-CuO /N\ SOaH CGHN- N=N N=N NEG-c H3 CHa SOzH HOaS- S cotton, linen and also artificial silk and staple is precipitated by the addition of sodium chloride fibers of regenerated cellulose. Very interesting and filtered t dy Cellulosic fib rs neutral shades are obtained of very good iastness to light. to weakly bluish grey S de-s having good fast In the following Example the parts and perness to li t. centages are by weight unless otherwise stated, A y Similar dyestuff is Obtained by replacing the relation between parts by Weight and parts for the second coupli the 28 Parts Of by volume being the same as that between the hydroxynaphthyl [2] aminophe kilogram and the liter. methyl benzthiazole X:6" disulfonic acid by 22 parts of 1 benzolylamino 8 hydroxy- Example naphthalene-3:6-disulfonic acid and otherwise 12.2 parts of 3:3'-dimethoxy-4:4'-diaminodi proceeding in the same manner as described. phenyl are tetrazotized in known manner. 27.5 Other unsymmetrical dyestuifs of similar propparts of 2 [4 (8" hydroxynaphthyl [2"1- erties but yielding somewhat more bluish shades aminophenylll 6 methyl benzthiazole-X:6"- on cotton are obtained by usin for the second disulfonic acid are dissolved in 200 parts of water coupling 2 (3' carboxyphenyl) aminowith the addition of the quantity of sodium hy- 5 hydroxynaphthalene l sulfonic acid or droxide solution necessary for the formation of l hydroxynaphthalene 4 sulfonic acid or the neutral sodium salt and 14 parts of crys- 2-hydroxynaphtha1ene-6-sulfonic acid. The dyetallized sodium acetate are added. This solution stufis so obtained correspond to the formulae H03 SOaH HOaS O--Cll-O 0Cl10 N 30311 CH3 HOxS- S SOsH 0 Cu O O-Cl1O N SOaH I I CH3 H03S- S Boss is combined with the tetrazo solution at 0 C. The 2 [4' (8" hydroxynaphthyl [2"]- while stirring vigorously. After several hours aminophenyD] 6 methylbenzthiazole X:6-

6 disulfonic acid used as starting material in this What I claim is: example can be produced as follows: 1. A cupriferous benzthiazole disazo dyestufl of 24.0 parts of 1:7-dihydroxynaphthalene-3-sulthe formula fonic acid are suspended in 500 parts of com- 10 in which R stands for the radical of a coupli g mercial sodium bisulfite solution. At 95 C. 46 component of the naphthalene series, the naphparts of 2-(4-aminopheny1)-6-methy1-benzthiathalene nucleus of which contains at least one zole-C-sulfonic acid (obtained by sulfonation of sulfonic acid group, the azo and the -0Cu 2-(4'-aminopheny1)-6-methyl-benzthiazo1e with group being bound to the naphthalene nucleus fuming sulfuric acid) are introduced and the reand standing in ortho-position to each another.

action mixture is maintained for hours with 2. A cupriferous benzthiazole disazo dyestufi of the formula O-Ou0 O-Cu o N SOIH I I I CH1 HOzS- S/ stirring and reflux cooling at 95-97 C. After in which the azo and the -OCu group are cooling, the condensation product which is diffiin ortho-position to each another. cultly soluble in acid solution, is filtered off. For 3. The cupriferous benzthiazole disazo dyestufl purification the filter residue is dissolved in the of the formula H035 N O-Cl1O O-C11-O N 30311 I I I H3O CH3 \S -SO3H 11038 3 hot in a medium alkaline with sodium carbonate 4. The cupriferous benzthiazole disazo dyestuif and freed from any insoluble residue by filtration. of the formula CON O-Ou0 OCu O HO S a5 SO3H HOaS- By addition of dilute hydrochloric acid the con- 5. The cupriferous benzthiazole disazo dyestufi densation product is precipitated as an orangeof the formula 0011 0 ocu o N S0311 HO 0 c =N NHOO I Q HN- soul H03s S brown deposit. If desired the condensation prod- 6. The cup-riferous benzthiazole disazo dyestuff uct can be freed from sulfurous acid by heating of the formula ?Cu (I) OCu 0 /N\ 50311 N=N N= NH-O 0H3 HO3$- S SOaH I the suspension, until the sulfurous acid has com- 7. The cupriferous benzthiazole disazo dyestufl pletely evaporated. of the formula (')Cu 0 O--Cu0 /N :11

CH3 H038 s HOaS References Cited in the file of this patent UNITED STATES PATENTS 1,024,021 France Jan. 7, 1953 

1. A CUPRIFEROUS BENZTHIAZOLE DISAZO DYESTUFF OF THE FORMULA 